Camera angle should follow path angle
Set Parent To -> Follow Path

This effect can be achieved with the following method:


Add a curve for your path: SHIFTA -> Curve -> select a curve
Edit your curve to be your desired camera path
Make sure you have the green frame cursor set to the frame on the Timeline you want to begin having the camera follow the path
Select the curve and in Edit mode, select the point of the curve you want to be the first place you want the camera to be
Then snap the 3D cursor to that point: SHIFTS -> Cursor to Selected:  


Now select the camera, then snap it to the 3D cursor: SHIFTS -> Selection to Cursor:  


Adjust the rotation of your camera so that it looks forward along the path  
Now first select the camera, then hold down SHIFT while selecting the path, then make the path the parent of the camera with the Follow Path option:  CTRLP -> Follow Path:  



(NOTE: The order you select the two objects is very important when setting parent/child relationships: first select the child, then the parent)  
Now when you play your animation, the camera will follow the path and stay oriented to the direction of the path: